There exists a need for new structural templates to guide the synthetic organic chemist in the design of potential chemotherapeutic agents. Studies in the isolation and structure elucidation of alkaloids have yielded many novel and pharmacologically-active compounds. We aim to continue our chemical studies of alkaloids. During the period ahead, we plan to pursue the fractionation and isolation of individual alkaloids from several alkaloid-rich mixtures. New alkaloids will be subjected to intensive structural studies, and will also be submitted for pharmacological evaluation. Modification of active alkaloids will be directed toward elucidation of structural requirements for biological activity. New approaches to efficient syntheses of active structural types will be sought. We hope that new structure-activity relationships may be revealed, and that such relationships may point the way to new medicinal agents. BIBLIOGRAPHIC REFERENCES: "Conformation and Reactivity of the Macrocyclic Tumor-Inhibitory Alkaloid Tetrandrine," C. J. Gilmore, R. F. Bryan, and S. M. Kupchan, J. Am. Chem. Soc., 98, 1947 (1976). "Biomimetic Synthesis of a Key Erythrina Alkaloid Precursor," S. M. Kupchan, C.-K. Kim, and J. T. Lynn, J. C. S. Chem. Comm., 86 (1976).